The present invention relates generally to the storage of hydrogen gas as a hydride of metal particles in a container.
Known hydrogen storage containers are filled with particles or chips of a hydride forming metal alloy having a molecular lattice structure which entraps hydrogen atoms. Hydrogen gas is fed into the container and is absorbed into the metal particles. Thereafter, upon application of heat to the container, hydrogen is released from the metal hydride and pressurized in the container. The container is provided with one or more valved ports to allow ingress and egress of the hydrogen. Such containers have found use as portable storage of hydrogen as a fuel for powering hydrogen engines on vehicles and the like.
Typically, the hydride forming metal particles in the container are dense and heavy, weighing on the order of 190 pounds per cubic foot. Such particles are effective in adsorbing and thus storing only about 2% hydrogen by weight. Therefore, a cubic foot of particles will store and release about 3.8 pounds of hydrogen. Such small storage capacity is unsatisfactory in hydrogen engine powered vehicles, for example. This is because the container weight required to provide suitable hydrogen fuel reserve is on the order of many hundreds of pounds.